From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Marcin Borkowski Newsgroups: gmane.emacs.help Subject: Re: Is there a way of setting a variable only when it exists? Date: Tue, 15 Mar 2022 07:16:17 +0100 Message-ID: <87bky7viz2.fsf@mbork.pl> References: <87lexdul8e.fsf@mbork.pl> <87lexcnq3w.fsf@web.de> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="4126"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: mu4e 1.1.0; emacs 29.0.50 Cc: help-gnu-emacs@gnu.org To: Michael Heerdegen Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Tue Mar 15 07:52:05 2022 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nU12K-0000mZ-TA for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 15 Mar 2022 07:52:04 +0100 Original-Received: from localhost ([::1]:51072 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nU12J-0007ld-OX for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 15 Mar 2022 02:52:03 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:41048) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nU0U1-0003VM-Pi for help-gnu-emacs@gnu.org; Tue, 15 Mar 2022 02:16:37 -0400 Original-Received: from mail.mojserwer.eu ([195.110.48.8]:58274) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nU0Tt-0004lb-Ta for help-gnu-emacs@gnu.org; Tue, 15 Mar 2022 02:16:34 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by mail.mojserwer.eu (Postfix) with ESMTP id E9B04E70F3; Tue, 15 Mar 2022 07:16:21 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at mail.mojserwer.eu Original-Received: from mail.mojserwer.eu ([127.0.0.1]) by localhost (mail.mojserwer.eu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id mjS8z_fzcQW7; Tue, 15 Mar 2022 07:16:18 +0100 (CET) Original-Received: from localhost (178235147016.dynamic-3-poz-k-0-1-0.vectranet.pl [178.235.147.16]) by mail.mojserwer.eu (Postfix) with ESMTPSA id D75F4E70B0; Tue, 15 Mar 2022 07:16:18 +0100 (CET) In-reply-to: <87lexcnq3w.fsf@web.de> Received-SPF: pass client-ip=195.110.48.8; envelope-from=mbork@mbork.pl; helo=mail.mojserwer.eu X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "help-gnu-emacs" Xref: news.gmane.io gmane.emacs.help:136564 Archived-At: On 2022-03-14, at 23:09, Michael Heerdegen wrote: > Marcin Borkowski writes: > >> I'd like to be able to say something like >> >> (setq-safe hello "world") >> >> so that `hello' is set to `"world"' if it is an existing variable (e.g., >> defined by `defvar') and an error is raised if `hello' does not exist. > > Byte compiling can help with things like name changes. Not necessarily. My use-case is an internal Emacs variable I'm setting in my `init.el'; at the same time I submitted a bug report/feature request to make it a user option, so I assume that it might change its name in a future Emacs version. >> I assume it would be fairly easy to code such a macro (using `boundp'), > > Maybe rather using `special-variable-p'? Might be a good idea in this case, yes. Thanks, -- Marcin Borkowski http://mbork.pl